Background Information

Before he was part of the crew aboard Serenity, Jayne was a mercenary. He met the crew of Serenity when he along with a few other men tried to rob the ship, but when he was offered a place in the crew and a large portion of earnings from heists, he shot one of the men he was with, and became part of the crew. His position aboard Serenity is “Public Relations”, which is a private joke to those aboard the ship.  
 
Even though Jayne did not fight in the Unification War that his “commanding officers” Zoë Washburne and Malcolm Reynolds fought in, that does not mean he isn’t good in a fight. He is often ruthless, but he has a code of honour. This code is that he will be loyal to his employer as long as he is paid well. Jayne has also stated “ I’ll kill a man in a fair fight. Or if I think he's gonna start a fair fight. Or if he bothers me. Or if there's a woman. Or if I'm gettin' paid. Mostly when I'm gettin' paid."  
 
Jayne is quite crude and often insults those around him but he cares about the crew of Serenity. This affection towards the crew is evident when he watches anxiously outside of the infirmary after Kaylee is shot.  He also has a rather surprising fondness for his mother. He sends her money and proudly wears an orange knit hat that was made for him by her.   

"These are stone killers, little man. They ain't cuddly like me." – Jayne Cobb (The Train Job)  

 
Jayne at one point betrayed Simon and River Tam by selling them out to the Alliance on Ariel, but it was apparent that he had second thoughts about what he was doing to them, even before the Alliance backed out of the deal. Mal knew he made the deal and threatened to have him sucked out the airlock. Jayne agreed to this, asking Mal to lie to them about his death, and to not let the rest of the crew know about the deal. Mal let him live. Jayne fears Reavers, and dying in an “unmanly” manner. 
 
On Higgins’ Moon, in the town of Canton, Jayne is thought of as a hero (much like Robin-Hood) and has a statue in his honor. The real story was that he had to leave the cargo that he stole in order to escape, since his ship was damaged and the goods were weighing it down. The town’s people even have a song titled “Hero of Canton, The Ballad of Jayne Cobb”. 
 

Weapons

Jayne possesses quite a few weapons, which he stores in his bunk aboard Serenity. His favourite gun, which he affectionately calls Vera, is a customized Callahan Full-bore Auto-lock. He attained Vera from the best in a group of men who tried to kill him. Jayne is extremely proud of Vera and has said “it is the best damn gun made by man. It has extreme sentimental value.” Jayne is often seen carrying a handgun, a blade and an assault rifle which is called Lux.  
  
 
 
 

Hero of Canton, The Ballad of Jayne Cobb

 
Jayne Cobb was portrayed in the TV series “Firefly” and in the motion picture “Serenity” by Adam Baldwin.